1. Field of the Invention
The present invention relates to a liquid crystal display device.
2. Description of the Related Art
Liquid crystal display devices are widely used as a thin display device employed in information communication terminals or televisions. Such a liquid crystal display device is configured to change the orientation of liquid crystal composition sandwiched between two substrates by changing an electric field generated by a potential difference between a pixel electrode and a counter electrode, thus controlling the transmission of light emitted from a backlight unit to display images.
Cold cathode fluorescent lamps have been used for a backlight source, whereas light-emitting diodes are often used in recent years.
JP 2008-251245 A discloses a direct-lit backlight, including light-emitting diodes, in which a heat radiation block is located in an aperture of a lamp housing.
Light-emitting diodes used for liquid crystal display devices generate more heat as their brightness increases. The heat generated by the light-emitting diodes, which increases the ambient temperature, may affect the chromaticity and the brightness of the diodes themselves as well as the operation of an integrated circuit (IC) that controls the diodes. Moreover, driving the light-emitting diodes and the IC under high temperature may accelerate their deterioration and shorten the useful life of liquid crystal display devices.